1. Field of the Invention
This invention relates generally to gas turbine engines and, more particularly, to laminated porous metal panels for use in high temperature environments of such engines.
2. Description of the Prior Art
U.S. Pat. Nos. 3,584,972 to Bratkovich et al; 4,044,056 to Carroll; 4,269,032 to Meginnis et al; and 4,302,940 to Meginnis; all assigned to the assignee of this invention, describe laminated porous metal panels for gas turbine engine applications. In the described panels, a hot inner lamina and a relatively cooler outer lamina have holes or pores therein which communicate through internal passages in the panel. Pressurized cooling air to which the outer lamina is exposed migrates through the inlet pores in the outer lamina and through the internal passages to convection cool the panel. The cooling air then discharges from the panel through the exhaust pores in the inner lamina and provides a film cooling barrier between the heat source and the inner lamina. The porosity of the panel, a measure of the rate at which cooling air flows across the panel, is based on an anticipated heat source temperature to which the panel will be exposed and is fixed once the panel is manufactured. If the panel encounters temperatures above or below the anticipated temperature, either too much or too little cooling air flows across the panel.